I wouldn't want them to have weapons because I can guarantee you there would be some (not all, but probably still plenty) players who would aggressively chase enemy commanders and/or pick off bots when convenient, and I simply can't be bothered to deal with that. You say it wouldn't happen? Then why even enable weapons?
You can guarantee? Based on what, your experience in said other commander modes? Some valid examples here please. If you've seen this happen plentiful, sure then, you win.
I've just played those I could find, mostly the official Napoleonic Wars one, and I've never seen anyone charge out with their commander to slay bots. Because simply they would die.
All that matters is that you at least have
something. Not having something takes away from the whole feel overall.
There's other measures so people don't charge off once troops dead, since commander would die, and with squishy armor there's even less incentive to charge out.
Would a few bots die? Maybe one or two, three max. More already die to horse bumping at the moment.
As long as the weapon is very slow, e.g. feels super heavy, and doesn't do too much damage, there's no issue here, which is exactly how it works in the other mods.
You can't fight multiple bots, it is already hard enough fighting one due to the weapon being slow, but at least you can fight instead of just standing there trying to throw high fives.